Discussion of Background Art
Today, a network auction (hereinafter simply referred to as auction) is widely utilized as one form of electronic commerce utilizing a communication network such as the Internet. There are many sites that provide an auction system.
A variety of auction systems provided by these conventional auction sites can not flexibly set a unit of exhibits, when there are multiple items a seller wants to sell. For example, considering the case when a tableware set, a series of items, or books are put on sale, even if a seller puts them up for auction individually to easily achieve the trade, there might be a case where a buyer who intends to buy in bulk be treated preferentially despite the selling price of a single item becoming somewhat cheaper, in order to maximize the total price. On the other hand, from a buyer's viewpoint, even if these sets or series of items are exhibited collectively, he or she might want to buy only a part of them.
However, in conventional auctions, when exhibiting multiple items collectively in this way (hereinafter, the whole of items is referred to as grouped items), it was impossible to dynamically change a unit of items subject to auction depending on requests from sellers and bids from buyers. For that reason, it was impossible to treat a buyer preferentially who intends to buy in bulk when multiple items are exhibited individually, or for a buyer who wants to buy only a part of items to participate in an auction, when they are exhibited as grouped items.